The Daily Parker

Politics, Weather, Photography, and the Dog

Brendan Michael

Last night, my other sibling had a baby:

That's Brendan Michael, aged one hour.

Update, from the exhausted but happy dad: Brendan emerged at 2:53 PST weighing 3540 g and stretching out to 508 mm.

All done with the code reorg

Well, that was fun. I've just spent the last three days organizing, upgrading, and repackaging 9,400 lines of code in umpteen objects into two separate assemblies. Plus I upgraded the assemblies to all the latest cool stuff, like Azure Storage Client 2.0 and...well, stuff.

It's getting dark on the afternoon before the U.S. Thanksgiving holiday, and I'm a little fried. Goodbye, 10th Magnitude Office, until Monday.

Still jamming; pre-Thanksgiving link roundup

Stuff sent to Instapaper:

Time to dash out for lunch...then more coding. Gotta finish today.

Jamming on the Codez

Over the last two days I've spent almost every working minute redesigning the 10th Magnitude framework and reference application. Not new code, really, just upgrading them to the latest Azure bits and putting them into a NuGet package.

That hasn't left much time for blogging. Or for Words With Friends. And I'm using a lot of Instapaper. Without Instapaper, I'd never get to read Wired editor Mat Honan drawing lessons from his epic hack last summer.

Chaining LINQ predicates

I've spent a good bit of free time lately working on migrating Weather Now to Azure. Part of this includes rewriting its Gazetteer, or catalog of places that it uses to find weather stations for users. For this version I'm using Entity Framework 5.0, which in turn allows me to use LINQ extensively.

I always try to avoid duplicating code, and I always try to write sufficient unit tests to prevent (and fix) any coding errors I make. (I also use ReSharper and Visual Studio Code Analysis to keep me honest.)

There are two methods in the Gazetteer's PlaceFinder class that search for places by distance. The prototypes are:

public static IEnumerable FindNearby(ILocatable center, Length radius)


public static IEnumerable FindNearby(ILocatable center, Length radius, Expression<Func<Place, bool>> predicate)

But in order for the first method to work, it has to create a predicate of its own to draw a box around the center location. (The ILocatable interface requires Latitude and Longitude. Length is a class in the Inner Drive Extensible Architecture representing a measurable two-dimensional distance.) So in order for the second method to work, it has to chain predicates.

Fortunately, I found Joe and Ben Albahari's library of LINQ extensions. Here's the second method:

public static IEnumerable<PlaceDistance> FindNearby(
	ILocatable center,
	Length radius,
	Expression<Func<Place, bool>> predicate)
	var searchPredicate = 
		SearchDistancePredicate(center, radius)

	var places = Find(searchPredicate);

	return SearchDistanceResults(places, center, radius);

This allows me to use a single Find method that takes a predicate, engages a retry policy, and returns exactly what I'm looking for. And it allows me to do this, which just blows my mind:

var results = PlaceFinder.FindNearby(TestNode, TestRadius, p => p.Feature.Name == "airport");

Compared with the way Weather Now works under the hood right now, and how much coding the existing code took to achieve the same results, I'm just stunned. And it will make migrating Weather Now a lot easier.

Upgrading to Azure Storage Client 2.0

Oh, Azure Storage team, why did you break everything?

I love upgrades. I really do. So when Microsoft released the new version of the Windows Azure SDK (October 2012, v1.8) along with a full upgrade of the Storage Client (to 2.0), I found a little side project to upgrade, and went straight to the NuGet Package Manager for my prize.

I should say that part of my interest came from wanting to use some of the .NET 4.5 features, including the asynchronous helper methods, HTML 5, and native support for SQL 2012 spatial types, in the new version of Weather Now that I hope to complete before year's end. The Azure SDK 1.8 supports .NET 4.5; previous version didn’t. And the Azure SDK 1.8 includes a new version of the Azure Emulator which supports 4.5 as well.

To support the new, Azure-based version (and to support a bunch of other projects that I migrated to Azure), I have a class library of façades supporting Azure. Fortunately, this architecture encapsulated all of my Azure Storage calls. Unfortunately, the upgrade broke every other line of code in the library.

0. Many have the namespaces have changed. But of course, you use ReSharper, which makes the problem go away.

1.The CloudStorageAccount.FromConfigurationSetting() method is gone. Instead, you have to use CloudStorageAccount.Parse(). Here is a the delta from TortoiseHg:

- _cloudStorageAccount = CloudStorageAccount.FromConfigurationSetting(storageSettingName);
+ var setting = CloudConfigurationManager.GetSetting(storageSettingName);
+ _cloudStorageAccount = CloudStorageAccount.Parse(setting);

2. BlobContainer.GetBlobReference() is gone, too. Instead of getting a generic IBlobContainer reference back, you have to specify whether you want a page blob or a block blob. In this app, I only use page blobs, so the delta looks like this:

- var blob = _blobContainer.GetBlobReference(blobName);
+ var blob = _blobContainer.GetBlockBlobReference(blobName);

Note that BlobContainer also has a GetPageBlobReference() method. It also has a nearly-useless GetBlobReferenceFromServer method that throws a 404 error if the blob doesn’t exist, which makes it useless for creating new blobs.

3. Blob.DeleteIfExists() works somewhat differently, too:

- var blob = _blobContainer.GetBlobReference(blobName);
- blob.DeleteIfExists(new BlobRequestOptions 
-	{ DeleteSnapshotsOption = DeleteSnapshotsOption.IncludeSnapshots });
+ var blob = _blobContainer.GetBlockBlobReference(blobName);
+ blob.DeleteIfExists();

4. Remember downloading text directly from a blob using Blob.DownloadText()? Yeah, that’s gone too. Blobs are all about streams now:

- var blob = _blobContainer.GetBlobReference(blobName);
- return blob.DownloadText();
+ using (var stream = new MemoryStream())
+ {
+ 	var blob = _blobContainer.GetBlockBlobReference(blobName);
+ 	blob.DownloadToStream(stream);
+ 	using (var reader = new StreamReader(stream, true))
+ 	{
+ 		stream.Position = 0;
+ 		return reader.ReadToEnd();
+ 	}
+ }

5. Because blobs are all stream-based now, you can’t simply upload files to them. Here’s the correction to the disappearance of Blob.UploadFile():

- var blob = _blobContainer.GetBlobReference(blobName);
- blob.UploadByteArray(value);
+ var blob = _blobContainer.GetBlockBlobReference(blobName);
+ using (var stream = new MemoryStream(value))
+ {
+ 	blob.UploadFromStream(stream);
+ }

6. Microsoft even helpfully corrected a spelling error which, yes, broke my code:

- _blobContainer.CreateIfNotExist();
+ _blobContainer.CreateIfNotExists();

Yes, if not existS. Notice the big red S, which is something I’d like to give the Azure team after this upgrade.*

7. We’re not done, yet. They fixed a "problem" with tables, too:

  var cloudTableClient = _cloudStorageAccount.CreateCloudTableClient();
- cloudTableClient.CreateTableIfNotExist(TableName);
- var context = cloudTableClient.GetDataServiceContext();
+ var table = cloudTableClient.GetTableReference(TableName);
+ table.CreateIfNotExists();
+ var context = cloudTableClient.GetTableServiceContext();

8. Finally, if you have used the CloudStorageAccount.SetConfigurationSettingPublisher() method, that’s gone too, but you don’t need it. Instead, use the CloudConfigurationManager.GetSetting() method directly. Instead of doing this:

if (RoleEnvironment.IsAvailable)
		(configName, configSetter) => 
		(configName, configSetter) => 

You can simply do this:

var someSetting = CloudConfigurationManager.GetSetting(settingKey);

The CloudConfiguration.GetSetting() method first tries to get the setting from Azure, then from the ConfigurationManager (i.e., local settings).

I hope I have just saved you three hours of silently cursing Microsoft’s Azure Storage team.

* Apologies to Bill Cosby.

Time to stock up on Twinkies

Texas-based Hostess Brands has shut down in preparation for liquidation:

Hostess said a strike by members of the Bakery, Confectionery, Tobacco Workers and Grain Millers International Union that began last week had crippled its ability to produce and deliver products at several facilities, and it had no choice but to give up its effort to emerge intact from bankruptcy court.

The Irving, Texas-based company said the liquidation would mean that most of its 18,500 employees would lose their jobs.

In the Chicago area, Hostess employs about 300 workers making CupCakes, HoHos and Honey Buns in Schiller Park. Hostess also has a bakery in Hodgkins, where 325 workers make Beefsteak, Butternut, Home Pride, Nature’s Pride and Wonder breads.

Union President Frank Hurt said the company's failure was not the fault of the union but the "result of nearly a decade of financial and operational mismanagement" and that management was trying to make union workers the scapegoats for a plan by Wall Street investors to sell Hostess.

Twinkies, legend has it, were invented right here in Chicago in 1930.

I will now go see if the 7-11 across the street still has any left...

All the stuff I've sent to Instapaper

Starting before 8am with an international conference call usually means I'll have a full day. Fortunately there's Instapaper, which lets me shove all the interesting things I find during the day onto my Android pad for tomorrow's bus ride to work.

So far today: back to work.